Gyro-vertical



gested and manufactured for returning the spin the stator in horizontal position, and which autoposition. I ings wherein: v The use of air for erecting purposes, however, Fig. 1 is a side elevation of a caged ym-Ver ihas certain very deflnitedrawbacks whe us i cal constructed in accordance with my invention.

- as might, be desired. From this it follows that responding to the line 4-4 of Fig. 3 looking in Patented June 19, 1945 2,378,858

uurrso STATES PATENT OFFICE zsrasss GYno-vnn'ncAL Thomas 0. Mehan, Park R ge, 111., assignor to Victor Adding Machine 00., Chicago, 111., a corporation of Illinois Application June 11, 1943, Serial No. 490,432

g 11 Claims. (01. 74-5) My invention relates to gyroscopic artificial natingcurrent or induction motor. Theme of horizons, or gyro-verticals for maintaining a such a motor enables me to utilize an electrohorizontal reference plane on rapidly moving vemagnetic couple having an inherent tendency to hicles, such as aircraft or ships, and more parovercome the ever present precessional forces ticularly to that type of gyro-vertical which is 5 which act upon the spin axis of free gyroscopes. suspended in gimbal rings, with substantially neu- Still further and more limitedly, it is a purpose tral equilibrium. of the present invention to provide novel and It is a well known fact among those skilled in improved means for electrically driving a gyro the art of gyroscopic devices, that the spin axis rotor from a pendulous stator so that the electric of a free gyroscope has the ever present tendl0 magnetic couple created between the stator and ency to creep or precess'from its normal vertical rotor normally exerts a stabilizing influence upon position due to friction in the bearings thereof, the spin axis of said rotor in suillcient magnitude or by stresses set up through acceleration or deto prevent tilting of such axis during normal ceieration forces produced when there is a sudflightconditions. den increase or decrease in the speed of the vel5 A still further object of the invention resides hicle on which the gyroscope is mounted, and/or in the novel stator construction which includes by the earth's movement. .a gravitationally responsive means, such as a Heretofore, numerous devices have been sugweighted pendulum, for normally maintaining axis of a gyroscope back to its normal vertical 20 matically acts through the influence of gravity .position after it has been caused to precess thereto return the stator to such normal horizontal from through the above-mentioned forces. For position should it be tilted by acceleration or deinstance, it has been common practice to employ celeration forces produced during an increase or air under pressure for erecting or positioning decrease in the speed of the aircraft upon which roscopes, the air being suitably directed for flow 25 it is mounted, as for instance during cl1m 1n8. through jets and controlled by the use of pendiving, banking, rolling or other maneuvers dulous shutters or other gravitationally conthrough which the aircraft may be Put. trolled means normally closing the jets and mov 'The foregoing objects and others hereinafter ing to open the same in response to tilting or deappearing are attained in the embodiment of the parture of the gyroscope from its normal vertical so invention illustratedin the accompanying drawconjunction with electrically driven gyrcscopes, Fig. 2 is a/ similar view partly in section and since a supply of air under pressure is not avail Q uncaged to Show the yro main frame in the able unless an air impellor is put on the gyro. position it will assume relative to the gyro in Then, too, due to friction of the shutter pivots, the case of a turn or a bank of the aircraft.

the pneumatic type of erecting or positioning Fig. 3 is a plan view of Fig. 1.

means very often fails to respond to minute i Fig. 4 is an enlarged vertical section partly in changes of tilt, and therefore, is not as sensitive, o elevation, the section being taken on a plane corair erecting means for gyro-verticals is not the v the direction indicated by the arrows.

complete or entirely satisfactory solution to the Fig. 5 is ahorizontal sectional elevation through problem of automatic erection forthe spin axis the-gyro-vertical, the section being taken along of gyroscopea' as the line H of Fig.1 and perpendicular to the I According to my invention I propose to provide spin axis of the gyrorotor, and,

very simple means which will not only prevent Fig. 8 is an enlarged fragmentary vertical sectilting or precession of the spin axis of gyro-vertitional elevation of the casing means employed, cals during normal straight flight operations, but th section being taken along the lin 8-4 of which will quickly act to re said spin axis backso Fig. 3,

to its normal vertical'position after it has been Th particular gyro-vertical selected for illuscaused to precess therefrom due to'flight of the tration purposes is shown su ported by asubaircraft in a curved path. To achieve, these restantially rectangular main frame I. but it is to suits I propose to use an electric driven gyrobe expressly understood that such frame may asvertical, and preferably one driven by an alter- 6| sumethefcrm of acasing or housing to enclose the gyro and prevent entrance of foreign matter such as dust, moisture, etc. In -use, the frame or housing 10 is rigidly attached to the aircraft (or ship) in any conventional manner and a vertically disposed hollow post H is rigidly fixed thereto by screws l2 for reasons presently disclosed.

An outer gimbal ring l3 (Fig. 5) is shown as pivotly supported by the vertical branches Illa and lb of frame III in a manner to rock about the horizontal axis formed by the pins |4-|5, and balls |6-|1, of anti-friction bearings |8-|9 respectively. The pins |4-|5 ar externally threaded so as to be received by threaded holes in the branches |Ua and lb respectively, and their tapered or pointed ends engage the balls |6-|1 thus providing a combined radial and thrust bearing sometimes termed a cup bearing.

The bearings |8|9 are desirably pressed into sockets'in the outer gimbal ring [3 as clearly shown in Fig. 5, and the threaded pins |4| 5 may be finely adjusted relative to the balls |6|1 of said bearings, and locked in adjusted position for example by the lock nuts 20.

The reference numeral 2| designates, an inner gimbal ring which is pivotly supported by the outer gimbal ring I3 about an axis at right angles to the pivotal axis of said outer gimbal. The

' pivotal axis for the inner gimbal 2| is formed by externally threaded pins 2223, the ends of which are pointed or tapered in a manner similar to pins |4-| 5 to engage the balls 24-25 of anti-friction bearings 26--21. The pins 22-23 are carried by the outer gimbal I3 and may be finely adjusted relative to the balls 24--25 respectively, and locked in the desired adjusted position by lock nuts 28. Bearings 26-21 are likewise desirably pressed into sockets in the inner gimbal 2|, as clearly illustrated in Fig. 5.

From the description thus far it will be apparcut that the outer gimbal ring |3 is mounted to rock on a horizontal axis which is perpendicular or at right angles to the horizontal axis about which the inner gimbal ring 2| rocks.

Referring now particularly to Figs. 3 and 4 it will be noted that the inner gimbal ring 2| has a semi-circular strap portion 29 formed integral therewith which serves to rigidly support a vertically depending spindle or rotor shaft 30 for the gyro rotor 3|. It will be noted that this shaft serves as the spin axis for the rotor 3|. Rotors for gyro-verticals are usually made of heavy metal, such as brass or steel, and in accordance with the present invention the rotor 3| carries anti-friction bearings 32-33 and has an enlarged weighted portion 34 acting as a fly wheel mass. A plurality of laminations or stampings l5, preferably pressed or shrunk into the fly wheel mass 34 of the rotor 3|, serve as a rotating squirrel cage for the stator 36.

In the embodiment shown, the stator 36 desir- .ably comprises a plurality of metal stampings I1 (as best shown in Figs. 4 and 5) having slots 36 within which field coils 59 are wound. To return the stator to its normal horizontal position after it has been moved therefrom I employ a weighted pendulum 40 attached thereto by screws 4|. As clearly shown in the drawings, the pendulum has a centrally disposed tapered opening 450 therein through which the hollow post passes. The stator 36 is mounted for universal movement with respect to post by a small gimbal ring 42 having outwardly projecting pins 43-43. The pointed ends of said pins engage with antifriction bearings 44-44, the latter being pressed into sockets formed in the stator laminations. Gimbal ring 42 further carries inwardly projecting pins 45-45 the pointed ends of which engage the antifriction bearings 46-46 respectively, such bearings being pressed into sockets formed in the enlarged upper end of the hollow post I l as best shown in Fig. 4.

A working current is supplied to the field coils 39 through conductors 41 which pass upwardly through the hollow post II, and their upper ends are soldered, or otherwise fastened, to an insulating disk 48 which is pressed into a recess in the upper end of said post. Conductors 41 are in turn, electrically connected with the field coils 35 by extremely flexible leads 4! (Fig. 4) which are sometimes referred to as "cats whiskers.

The construction of the stator and rotatin squirrel cage is such that an arcuate air gap 50 is defined between the concave edge surfaces of the squirrel cage laminations 35, and the convex edge surfaces of the stator laminations 31, as clearly illustrated in Fig. 4.

It will be evident from the foregoing description that rotor 3| has a normally vertical spin axis and that through its suspension in gimbals I3 and 2|, respectively, it is supported for oscillation about two mutually perpendicular axes namely: the axis formed by the pins |4--|5 and the axis formed by th pins 22-43.

In gyro-verticals, it is generally desirable to have some form of caging mechanism whereby the gyro rotor canbe rigidly held when desired. One form of caging mechanism which ,may be conveniently used in connection with my improved gyro-vertical is shown in Fig. 6, wherein the upper end of spindle 30 terminates in a pointed pin 50a. This pin is held or caged, by a cup 5| when the hand knob 52 is moved to its lowered position shown in Fig. 6. The cup 5| and knob 52 are rigidly fixed to opposite ends of shaft 53, the latter being slidably mounted in the horizontal branch lie of the frame Hi. This shaft has annular grooves 54-55 to receive the detent ball 56, which is yieldably held within one or the other of said grooves by spring 51 depending upon whether the hand knob 52 is in its lowered or elevated position. The spring 51 is held against the detent ball 56 by a threaded plug 56 as shown.

. Thus, it will be understood that when the hand knob 52 is depressed, cup 5| will engage and hold the pin 300 relative to the base I00 ,of the frame III, at which time the detent ball 56 will engage the groove 54 in shaft 53. To uncage the gyro it is merely necessary to pull upwardly on the hand knob 52 to remove the cup 5| from holding engagement with the pin 30a. The knob and cup will then .be held in such elevated position by the detent ball 56 engaging the groove 55.

It has been previously mentioned that one of the principal objects of my invention is to provide a gyro-vertical, the construction ofwhich is extremely simple and of such design that tilting or precession of the rotor spin axis is prevented during normal straight flight operation of the aircraft on which the gyro-vertical is mounted, and which will also quickly act to restore said spin axis of said rotor back to its true vertical position should it be caused .to move or precess therefrom by unfavorable torques caused by fraction set up in the bearings, flight in a curved path and/or by the earth's movement.

To describe the operation of my improved gyrovertical let us assume that the aircraft upon known that these two unfavorable torques are always present and acting upon free gyroscopes to cause precession of the rotor "spin axis. During straight flight operations of the aircraft these two precessional torques are overcome in my improved gyro-vertical by the gravitationally responsive means, namely, the pendulum l afiixed to the stator 36. In other words, gravity acting upon the weighted pendulum holds the stator 36 horizontal relative to the earth's surface and the electro-magnetic couple between the convex edge surfaces of the stator laminations and the concave edge surfaces of the squirrel cage laminations is of such magnitude that it overcomes the above? mentioned precessional forces tending to precess the rotor spin axis. Thus, it will be seen that during straight flight operation of the aircraft the spin axis of the gyro-rotor will be prevented from precessing due to stabilization of the stator by the pendulous weight and electro-magnetic couple between the stator and rotor.

Let it be assumed now that the aircraft is meneuvered so as to execute a left bank, or flight in a curved path so tospeak for a short interval of time and then brought back to substantially level flight. During such maneuver, centrifugal force will act upon the pendulous weight 40 which in turn efiects momentary disalignment or the stator relative to the rotor. Providing the interval of time during which the plane is flown in curved flight is of short duration, very little precessional torque will be imparted to the rotor through the electro-magnetic couple between the rotor and stator, but should the curved flight be continued for a long period of time the electro-magnetic couple will gradually act to cause the spin axis of the rotor to process in proportion to the time of such curved flight. However, when.

level flight is again resumed, gravity will act on the pendulum 40 to return the stator back to level position and the electro-magnetic couple between vention. I therefore desire, by the following claims, to include within the scope of my invensaid stator and rotor will then become effective Y to return the spin axis of the rotor to its true vertical position which is attained when the laminations of the rotor are brought into registry or parallel alignment withrthe lamlnations of the stator.

To those skilled in the art or gyroscopic devices it will be understood that the spin axis oi my gyro rotor will be caused to precess from its normal vertical position whenever the plane is flown in a continuous curved path or circle for an indefinite period of time. This is brought about or caused by centrifugal force acting upon the stator pendulum whereupon the stator is moved out of alignment with the rotor. It is customary however to cage the rotor during prolonged curved flight operations of the aircraft and to un,

cage it only when the plane is to be flown in subatantially level flight.

While I have shown and described a particular embodiment of my invention it will be apparent to those skilled in theart that numerous modifications and variations may he made in the form and construction thereof, without departing from the more fundamental principles of the intion all such similar and modified forms of the apparatus disclosed, by which substantially the results of the invention may be obtained by substantially the same or equivalent means.

I claim:

1. In a gyro-vertical the combination of, a universally mounted gyroscope rotor having a normally vertical spin axis, a pendulous stator, and electric means for exerting an erecting torque on 'said rotor to prevent precession of its spin axis from normal vertical position, said electric means including an electromagnetic couple between sai rotor and pendulous stator.

2. In a gyro-vertical for aircraft and the like, the combination of a gyroscope comprising a rotor mounted for universal movement and having a normally vertical spin. axis, a pendulous stator universally mounted independently of said rotor, and electric means constantly acting to prevent precession of said rotor spin axis when the aircraft is flown in substantially straight flight and at constant velocity, said last-named means comprising an electromagnetic couple between said rotor and pendulous stator.

3. In a gyro-vertical for aircraft, the combination of a high speed rotor suspended by a pair of gimbal rings so as to have universal movement and a normally vertical spin axis, a stator uni-- versally mounted upon a third gimhal ring and entirely independent of said rotor, means carried by the aircraft to pivotally support said last named gimbal ring, and an electromagnetic conpie between said rotor and stator constantly acting to prevent precessional movement of said spin axis when the aircraft is flown substantially level and at constant velocity.

1. In a gyro-vertical, the combination of a rotor supported by a pair of gimbals so as to have a normallyvertical spin axis, a stator universally mounted independently of said rotor, stampings for the stator, field coils Wound upon s stampings, a working current for said coils, a squirrel cage carried by said rotor including a plurality of laminations, and gravitationally liesponsive means carried by the st or acting to normally maintain the latter horizontal position relative said rotor.

5. In a gyro-vertical for aircraft having a pair of gimbal rings mounted for freedom about niutu ally perpendicular normally horizontal axes, a gyro rotor suspended from one of sold rings and arranged to spin abou a normally vertical axis, means mounted upon the aircraft and; ar ranged to pivotally support the outer of said rings, on induction motor comprising a rotating squirrel cage carried by the rotor, a stator arranged with respect to the squirrel cage so as to define an arcuate air gap between said and souirrcl cage, field coils for the stator, electrical conduc tors connecting coils with a working current, means for universally mounting said stator relevtivelto said aircraft, gravitationally responsive means carried by the stator, and electric coupie created within said arcuate gap during energization oi said field cells, which is eflective to restore the spin axis of the rotor to normal vertical position should it be processed there from.

6. In combination, a gyro-vertical comprising a gyro rotor, means supporting said rotor for freedom about mutually perpendicular and normally horizontal axes in substantially neutral equilibrium, said rotor having a normally vertical spin axis, electrical means for rotating said rotor including a stator, means for universally supporting said stator, and means for making said stator pendulous, thereby to apply a constant erecting torque on the rotor by the electro-magnetic couple created between the stator and rotor.

7. In combination, a gyro-vertical comprising a gyro rotor, means supporting said rotor for freedom about mutually perpendicular and normally horizontal axes in substantially neutral equilibrium including a frame and a pair of gimbals, said rotor having a normally vertical spin axis, electrical means for rotating said rotor including a stator, means for universally supporting said stator relative to said rotor and entirely independent therefrom, and a pendulous weight for said stator whereby a constant erecting torque is applied to the rotor through the electro-magnetic couple created between the stator and rotor.

8. In a gy o-vertical, the combination of a gyro rotor having a normally vertical spin axis, a housing, a pair of gimbal rings mounted in said housing to support said rotor for precessional movement about two mutually perpendicular horizontal axes and in substantially neutral equilibrium, 9, spindle fixed to one of said gimbal rings and serving as the spin axis for said rotor, electric means for rotating said rotor including an induction motor having a pendulous stator universally mounted upon said housing and entirely independent of said rotor, field coils wound upon said stator, a working current for said "coils, and a squirrel cage carried by the fly wheel mass of said rotor, characterized by the fact that when said working current is connected with said coils, rotation of said rotor takes place and the magnetic couple created between the stator and rotor exerts a constant erecting torqu upon said rotor to prevent departure of its spin axis.

9. In a gyro-vertical for aircraft comprising a universally supported gyroscope rotor moimted to spin about a normally vertical axis, a universe-11y supported stator, means to prevent tilting or precession oi the rotor spin axis from its normal vertical position during straight flight operation of said aircraft performed at constant velocity and to return said spin axis back to its true vertical position should it be precessed therefrom through curved flight of said aircraft, said last-mentioned means comprising an electro-magnetic couple between said rotor and stator and gravitationally controlled means on said stator.

10. A gryro-vertical comprising the combination of a gyro rotor supported by gimbals in substantially neutral equilibrium and with its spin axis normally vertical, a pendulous stator also supported by gimbals in substantially neutral equilibrium and entirely independent from the rotor, and electric means adapted to exert an'erecting torque upon said rotor to prevent precession of its spin axis from normal vertical position, said erecting means comprising an electro-magnetic couple between the rotor and pendulous stator.

11. In a gyro-vertical for aircraft and the lik the combination of a gyroscope comprising a rotor universally mounted within a pair of gimbals to have a normally vertical spin axis, a stator universally mounted independently 0! said rotor, stampings for the stator, fleld coils wound upon said stampi 5, electric conductors for supplying a working c cut to said coils, a squirrel cage carried by said rotor including a plurality of laminations, gravitationally responsive means carried by the stator to normally maintain the latter in horizontal position and an electro-magnetic couple created within an 'arcuate air gap defined between the stator stampings and the rotor laminations when said working current is supplied to said'stator field coils to thereby prevent precession of the normally vertical spin axis of the rotor when the 

